Two field experiments were carried out during 2003 and 2004 seasons at
seven Governorates (EI-Monfia, EI-Gharbia, EI-Dakahlia, EI-Shrkia, EI-Behira, Kafer-
EI-Sheikh and Damiatta) to investigate the relative importance of different lint cotton
yield and seed cotton yield components in seven Egyptian cotton varieties (Giza45,
Giza 70,Giza 85,Giza 86,Giza 87,Giza 88 and Giza 89). The recorded data were boll
weight, lint percentage, seed index, seed cotton yield in kentar per faddan, lint yield in
kentar per faddan and number of bolls per plant. Simple correlation coefficients and
stepwise multiple linear regression were used, in addition to path coefficient
analysis. The results showed positively and highly significant correlation coefficients
between either seed cotton yield or lint yield and yield components.
Simple correlation coefficient was used for assessing the relationship
between lint yield and characters studies. Lint yield was highly positive correlated
with each of boll weight, lint percentage, seed index and number of bolls per plant.
When the relative contribution from boll weight and number of bolls per plant were
combined in linear regression equations, their contribution to seed cotton yield and
lint yield were 97.80 % and 92.49 %, respectively.
Results of the path coefficient analysis, revealed that three yield components
(boll weight, seed index and number of bolls per plant) contributing to seed cotton
yield (kif) and lint yield (kif). The highest value for coefficient of determination (CD)
were 0.0827 for boll weight and 0.779 for number of bolls per plant with relative
importance equal to (RI) of 8.27% and 77.98 %, respectively in the first model (seed
cotton yield). Boll weight and number of bolls per plant had the highest indirect effect
being 10.57 %. The total relative contribution of the studied characters to the overall
variation in seed cotton yield (kif) was 97.80 %. While in the second model, results
indicate that the highest values for coefficient of determination (CD) was 0.1146 for
boll weight and 0.7069 for number of bolls per plant with, relative important (RI%)
equal to 11.02 % and 68.56 %, respectively in lint yield. The total relative contribution
of the studied characters to the overall variation in lint yield was 92.46 %.
In general obtained results indicated that number of bolls per plant and boll
weight were the major and the most consistent sources accounting for variation in
seed cotton yield and lint yield. Therefore, it is important for the breeder to consider
these characters in formulating his breeding programs to obtain the best yield.